The invention relates to a method for authenticating a security element, a device, a computer program product and a server for carrying out the method, as well as an optically variable security element for use with such a method.
Optically variable security elements are used frequently in order to authenticate documents, banknotes or products and protect them against forgery. As these security elements generate different optical effects at different observation and/or illumination angles, they cannot be easily reproduced by photocopying, duplication or simulation.
Such security elements usually have a defined optical design, which can be verified visually by a simple observation. Forgeries of high quality which only differ in a few details from the original cannot, however, always be recognized in a reliable manner with a visual inspection. If a multitude of documents or products have to be authenticated, for example a large quantity of objects such as banknotes, documents or products, a visual inspection is also not expedient. A visual inspection is often also not sufficient, because often the user does not know which specific security element with which optical and other security functions is actually allocated to the respective object at all. Because of the multitude of existing security elements on all the possible different objects, it is often difficult to recall precise knowledge about the specifically present security element and its specific properties from memory in each case.
Furthermore, systems for automatic authentication of security elements are known. For this, the security element is usually illuminated with a laser at a predetermined angle and the diffracted light is detected at one or more predetermined observation angles by means of appropriate sensors. These are stationary systems which are suitable for checking a large quantity of in particular identical objects in a short time.
However, it is often also necessary to authenticate the security elements of individual objects impromptu in-situ. Such stationary systems are not suitable for this.